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The Kalausis the river in the Stavropolskii region of Russia being an important source of water. Water use has caused water decrease, water depletion and water deterioration. Therefore water shortages exceed natural river flow by 100%. The water quality category is estimated as “very dirty”. The main source of river water pollution is diffuse runoff from agricultural lands. Estimationson both the environmental river flow and the efficiency of water protection measures are given in this paper. It considers the impact of the lands on the flow volume and quality of the river water, and also estimates the impact of global climate change on water scarcity. To improve the ecological status of the river up to “satisfactory” it is necessary to save the volume of environmentally friendly flow without its with drawing. To improve the water quality up to “moderately polluted” it is necessary integrated water protection measures.

Heat shock (HS) is one of the best-studied exogenous cellular stresses. The cellular response to HS utilizes ancient molecular networks that are based primarily on the action of stress-induced heat shock proteins and HS factors. However, in one way or another, all cellular compartments and metabolic processes are involved in such a response. In this review, we aimed to summarize the experimental data concerning all aspects of the HS response in mammalian cells, such as HS-induced structural and functional alterations of cell membranes, the cytoskeleton and cellular organelles; the associated pathways that result in different modes of cell death and cell cycle arrest; and the effects of HS on transcription, splicing, translation, DNA repair, and replication.

Transcription factor RUNX1 is one of the key regulatory proteins in vertebrates. It controls hematopoiesis and angiogenesis. It is indispensable during embryogenesis for the emergence of sites of definitive hematopoiesis and later in mature organisms for bone marrow blood stem cells differentiation. Moreover, RUNX1 gene is a frequent target for chromosomal translocations which cause acute forms of leukemia. A lot of types of human leukemia are somehow associated with mutations in this gene. Nevertheless, to this day the precise mechanism guiding the tissue-specific manner of the RUNX1 gene expression remains unknown. In this review we tried to summarize all the experimental data accumulated during the past twenty years beginning from the date when the cDNA sequence of the RUNX1 gene was first annotated. In the first part of the review we shall focus on structure, isoforms, covalent modifications of the RUNX1 transcription factor and its participation in different regulatory cascades. In the second part we shall discuss expression regulation, mutations and chromosomal translocations of the RUNX1 gene.

The transcription factor RUNX1 is a key regulator of haematopoiesis in vertebrates. In humans, the 260-kb long gene coding for this transcription factor is located on chromosome 21. This gene is transcribed from two alternative promoters that are commonly referred to as the distal and the proximal promoters. In model experiments, these two promoters were found to be active in cells of different lineages, although RUNX1 is preferentially expressed in haematopoietic cells. In the present study, we attempted to identify the regulatory elements that could guide tissue-specific expression of the RUNX1 gene. Two such regulatory elements were found within the RUNX1 gene. One of these elements, located within intron 1, is a haematopoietic-specific enhancer. The second regulatory element, located within intron 5.2, contributes to the formation of an active chromatin hub, which integrates the above-mentioned enhancer and the P1 and P2 promoters.

BACKGROUND:It becomes increasingly evident that nuclesomes are far from being identical to each other. This nucleosome diversity is due partially to the existence of histone variants encoded by separate genes. Among the known histone variants the less characterized are H2A.Bbd and different forms of macroH2A. This is especially true in the case of H2A.Bbd as there are still no commercially available antibodies specific to H2A.Bbd that can be used for chromatin immunoprecipitation (ChIP). METHODS:We have generated HeLa S3 cell lines stably expressing epitope-tagged versions of macroH2A1.1, H2A.Bbd or canonical H2A and analyzed genomic distribution of the tagged histones using ChIP-on-chip technique. RESULTS:The presence of histone H2A variants macroH2A1.1 and H2A.Bbd has been analyzed in the chromatin of several segments of human chromosomes 11, 16 and X that have been chosen for their different gene densities and chromatin status. Chromatin immunoprecipitation (ChIP) followed by hybridization with custom NimbleGene genomic microarrays demonstrated that in open chromatin domains containing tissue-specific along with housekeeping genes, the H2A.Bbd variant was preferentially associated with the body of a subset of transcribed genes. The macroH2A1.1 variant was virtually absent from some genes and underrepresented in others. In contrast, in closed chromatin domains which contain only tissue-specific genes inactive in HeLa S3 cells, both macroH2A1.1 and H2A.Bbd histone variants were present and often colocalized. CONCLUSIONS:Genomic distribution of macro H2A and H2A.Bbd does not follow any simple rule and is drastically different in open and closed genomic domains.

Chromosomal translocation t (8;21)(q22;22) is one of the most frequent cytogenetic abnormalities found in acute myeloid leukaemia (AML). It generates the AML1/ETO fusion gene, which itself supports human haematopoietic stem cell self-renewal. However, the mechanism guiding transcription of this chimeric gene remains unclear. In our work, we attempted to shed light on this essential issue. We investigated the promoter from which transcription of the AML1/ETO gene is initiated and defined the three-dimensional structure of the whole rearranged locus.

Twenty patients of the control group without pathology of the thyroid gland were examined for development of the method of 3D-ultrasonic reconstruction and 3D-angiography. The study group consisted of 74 patients with nodular pathologies of the thyroid gland, 53 of them underwent surgery. Ultrasonic data was compared with results of clinical and laboratory studies, puncture biopsy and intraoperative data. Three-dimensional ultrasonic pictures permitted to detect spatial orientation of the nodes relative to lobes and segments of the thyroid gland, vascular structures, to evaluate character of nodes vascularization, to analyze nature and invasiveness of the tumor. Based on these data optimal variant of surgery was chosen. In 12 cases virtual modeling of surgeries with 3D-echography and ultrasonic angiography was performed. These methods permit to choose optimal variant of surgery and make possible prediction and prevention of complications.

Инсуляторы были открыты как геномные элементы, способные прерывать связь между промотором и энхансером (энхансер-блокирующая активность) и ограничивать распространение гетерохроматина (барьерная активность). У дрозофилы существует несколько типов инсуляторов, работающих посредством привлечения различных белков. Все описанные инсуляторы у позвоночных животных работают при участии многофункционального транскрипционного фактора CTCF. Биологические функции инсуляторов позвоночных животных не вполне ясны. Хотя принято считать, что они разграничивают хроматиновые домены, прямых свидетельств этому практически нет. Наиболее показательным является участие инсуляторов в работе центров установления импринтинга (imprinting choice regions). Результаты ряда недавно опубликованных работ свидетельствуют о том, что для установления импринтинга существенным является встраивание инактивированного гена в отдельный топологический домен (петлю). В этом и многих других случаях инсуляторы работают в качестве архитектурных элементов, поддерживающих трехмерную организацию генома. Взаимодействие между парами инсуляторов, в котором наряду с CTCF значительную роль играет когезин, организует геном в различного рода петли. Ключевые слова: хроматиновый домен, барьерный элемент, энхансер-блокирующий элемент, CTCF, импринтинг. Інсулятори було відкрито як геномні елементи, здатні переривати зв’язок між промотором і енхансером (активність, яка блокує функціонування енхансера), та обмежувати поширення гетерохроматину (бар’єрна активність). У дрозофіли існує декілька типів інсуляторів, які працюють із залученням різних білків. Всі описані інсулятори у ссавців працюють за участі багатофункціонального транскрипційного фактора CTCF. Біологічні функції інсуляторів ссавців не до кінця з’ясовані. Хоча багато хто вважає, що вони розмежовують хроматинові домени, прямих свідчень цьому практично немає. Найпоказовішою є участь інсуляторів у роботі центрів встановлення імпринтингу (imprinting choice regions). Результати низки недавно опублікованих робіт свідчать про те, що для встановлення імпринтингу суттєвим є вбудовування інактивованого гена в окремий топологічний домен (петлю). В цьому та в багатьох інших випадках інсулятори працюють як архітектурні елементи, які підтримують тривимірну організацію геному. Взаємодія між парами інсуляторів, у яких поряд з CTCF істотну роль відіграє когезин, організує геном у різного роду петлі. Ключові слова: хроматиновий домен, бар’єрний елемент, енхансер-блокуючий елемент, CTCF, імпринтинг. Insulators were first identified as genomic elements either blocking communication between promoters and enhancers (enhancerblocking activity) or restricting heterochromatin spreading (barrier activity). There are several types of insulators in Drosophila which utilize different proteins. All insulators identified in vertebrates work with the help of the multifunctional transcription factor CTCF. Biological functions of vertebrate insulators are not clear yet. They are supposed to separate chromatin domains albeit there is almost none direct evidence of this fact. The most significant is the participation of insulators in maintenance of centers of imprinting (imprinting choice regions). The results of a number of recently published articles indicate that isolation of a gene by placement of this gene into a separate topological domain (loop) is crucial to establishing imprinting. In this particular case as well as in many other cases insulators serve as architectural elements supporting the three-dimensional structure of genome. Moreover, interaction between pairs of insulators where cohesin plays a pivotal role along with CTCF folds genome into various loops. Keywords: chromatin domain, barrier element, enhancer-blocking element, CTCF, imprinting.